30m QRP transceiver – Part 5
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Since the VFO, LF and receiver seem to work without any problems, it was getting time to build the final parts: the transmitter board, the transmit/receive-switch and the lowpass filter.
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Category Homebrew
70cm bicycle antenna
![[Image]](https://www.pa3hcm.nl/wp-content/uploads/2014/08/fietsmobiel.jpg)
During the summer season I sometimes travel to work by bike. It’s a 21 km trip through the countryside, passing cornfields, orchards, deer and spoonbills. The road includes dikes and bridges, and even a ferry to cross one of the…
30m QRP transceiver – Part 4
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Since I finished all modules for the receiver part (power, LF, VFO and RX-board), it was getting time to put everything together and place it in a nice case. Onno PA2OHH (designer of this radio) managed to put the complete…
PC6REC ATV station
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During the 2014 edition of the REC Fielddays I facilitated a live videofeed, broadcasted throughout the Netherlands. Using three cameras and a bunch of (mostly) vintage hardware, the live stream was uplinked to the local ATV repeater PI6ATV. Viewers could…
Stereo to mono converter
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My TV camera generates stereo audio, like most cameras do. However, my local ATV repeater only supports mono audio. So to transmit a nice audio signal with my TV pictures, I needed a way to convert the stereo signal to…
CLog 0.10b released, introducing Cabrillo support
![[Image]](https://www.pa3hcm.nl/wp-content/uploads/2014/01/clog-list-show.jpg)
Today I released version 0.10b of my command line logbook called ‘CLog’. This version introduces Cabrillo 2.0 export functionality.
Kenwood interface for visually impaired radio amateurs
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This article describes an add-on for modern Kenwood transceivers to allow visually impaired operators to use these radios with a VS-3 or VGS-1 voice synthesizer. I built this interface for Adrian PA0RDA (using a TS-2000), but I’m almost sure that…
PoRG v2
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A couple of years ago I built my first PoRG (abbreviation for “Power over RG-cable”), a simple phantom power supply to power some device over antenna cable (e.g. a preamp, active antenna, coax switch, etc). I recently built an active antenna…
30m QRP transceiver – Part 3
![[Image]](https://www.pa3hcm.nl/wp-content/uploads/2014/04/20140402_230047.jpg)
Now all LF parts and the VFO were finished, it was time to build the RF-part of the receiver.
30m QRP transceiver – Part 2
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Building a stable VFO is challenging. Oscillators tend to drift away due to (very small) temperature fluctuation, or due to small capacitive changes in the direct environment (e.g. the frequency changes when you move your hand towards the oscillator). The…
ATV transmitter for 23cm
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Although I was already able to receive the local ATV repeater PI6ATV, it has been a wish for about 8 years to be able to uplink too. So I once bought a couple of modules from PE1ACB that would allow…
A very small active antenna
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Small active antennas like the “mini-whip” (by PA0RDT) are very popular at the moment. They provide good reception of signals from HF all the way down to the VLF band. Here in the Netherlands Van Dijken Elektronica sells a nice…
30m QRP transceiver – Part 1
![[Image]](https://www.pa3hcm.nl/wp-content/uploads/2014/03/qrm30m-lf-modules.jpg)
This summer I want to go walking in the beautiful highlands of Scotland, together with my wife. The mobile phone coverage in this desolate area is none or poor, but hey… I’m a radio amateur! For a daily “sign of…
The “PoRG”
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The “PoRG” is a very simple but useful device in your ham shack. “PoRG” is an abbreviation for “Power over RG-cable” and allows you to put DC on your antenna cable. Some people call it a phantom power supply. With…
CLog 0.9b released
Today I released CLog version 0.9b, the command-line hamradio logbook. Although still beta, the software appears to be reliable now, even when used in multi-operator contests. These are the changes in CLog 0.9b:
HB9CV-in-a-box antenna for 23cm
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The HB9CV has been a popular antenna for decades, especially on the 2m band where it is commonly used for direction finding (foxhunt). Others create arrays of HB9CV antennas for DXing. Since I needed a simple antenna for 23cm (to…
ATV image generator using the Raspberry PI
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I’ve got a Raspberry PI for a while already, but it hasn’t been very useful until today. I recently started setting up my own ATV (Amateur TeleVision) station. I needed a simple solution to generate a test pattern, something to…
First ATV transmission
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I’m working on a 23cm ATV transmitter. A couple of years ago I already bought some modules from PE1ACB: a baseband modulator, a 23cm ATV transmitter (output 1 watt) and a controller unit. Today I hooked up all modules, together…
Is our 80/160m HEDZ suitable to work Americans at 160m?
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Last weekend was the yearly ARRL 160m contest. Adrian PA0RDA and I were still a bit in doubt about our HEDZ antenna for 80 and 160m: is it suitable to work American and Canadian stations at 160m? So far we…
Spijkerradio
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Introduction “Spijker” is a dutch word for nail, which you would normally use to hang something on the wall, or to construct wooden stuff. However, (brass) nails can also be used as as solder pad. PA0KLS used this idea to…
J-pole antennas for HF bands
Introduction I’ve been using J-pole antennas on the 2m band from the first day I got licensed. They perform very well, are easy to construct and are cheap. Since Adrian PA0RDA and I have been experimenting with vertical antennas for…
Automatic antenna tuner using an Arduino
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Introduction The Arduino board is a fantastic tool for rapid prototyping, and can help radio amateurs in lots of homebrew projects. I wanted to demonstrate that it is very easy to build an automatic antenna tuner with the Arduino. I…
Squalo antenna for 6m
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Introduction Adri PA0RDA, a friend of me, is trying to do some DX on 6m for a while now. His antenna position is very poor: he lives in the bottom flat of a 5-floor building. He has a balcony on…
Arrow antenna
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Introduction The arrow antenna is a popular antenna for using FM transponders on satellites. These satellites have a uplink on the 2m band, and a downlink on 70cm. You can operate those satellites with a simple dualband handheld radio.
TNC-X
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Introduction The Dutch Amateur Radio Emergency Service (DARES) is currently setting up a messaging system for emergency communications. Email is sent over radio using the good old AX.25 protocol. Part of this project is the TNC-X, a simple packet radio…